True and false identification of pearl necklace The authenticity of pearl necklaces can be identified by friction method, intuitiv usul, qo'lni his qilish usuli, va hokazo. 1. Ishqalanish usuli: [Haqiqiy marvaridlar] Haqiqiy marvaridlar asosan kaltsiy karbonatdan iborat bo'lgani uchun, va ularning tuzilishi konsentrik kristalli qatlamli (shingil) tuzilish, ikki marvarid bir-biriga surtiladi, [...]
